Medium transporting apparatus and image forming apparatus having the same

Abstract

A medium transporting apparatus includes a first transport member and a movable guide member. The first transport member transports a medium in the medium transport direction. The movable guide member comes into contact with and guides the medium transported by the first transport member along a medium transport path. The movable guide member is also movable from a first position to a second position downstream of the first position in the medium transport direction.

1. A medium transporting apparatus comprising:
 a first transport member that transports a medium; 
 a movable guide member that comes into contact with and guides the medium transported by the first transport member along a medium transport path, the movable guide member being movable from a first position to a second position downstream of the first position in the medium transport direction; and 
 a fixed guide member that guides the medium, the movable guide member moving along a medium transport surface of the fixed guide member, the fixed guide member including a plurality of ribs that come into contact with the medium and extend in the medium transport direction, 
 wherein the movable guide member has a plurality of cutouts at one end thereof, the ribs of the fixed guide member projecting outward into the medium transport path from between the cutouts. 
 
     
     
       2. The medium transporting apparatus according to  claim 1 , further comprising:
 a driving member that moves the movable guide member; 
 a medium detection sensor that detects the position of the medium on the medium transport path; and 
 a controller that controls the driving member based on an output from the medium detection sensor. 
 
     
     
       3. The medium transporting apparatus according to  claim 2 , wherein the driving member is a motor. 
     
     
       4. The medium transporting apparatus according to  claim 1 , further comprising a moving member that urges the movable guide member toward the first position. 
     
     
       5. The medium transporting apparatus according to  claim 4 , wherein the moving member is selected from the group of consisting of a spring, a weight, a solenoid and a motor. 
     
     
       6. The medium transporting apparatus according to  claim 1 , wherein the length of the movable guide member in the medium transport direction is less than the length of the shortest medium that can be transported by the medium transporting apparatus. 
     
     
       7. The medium transporting apparatus according to  claim 1 , wherein the movable guide member includes a plurality of ribs that come into contact with the medium and extend in the medium transport direction. 
     
     
       8. The medium transporting apparatus according to  claim 1 , wherein at least part of the movable guide member is adapted to back away from the medium transport path. 
     
     
       9. The medium transporting apparatus according to  claim 1 , wherein at least part of the movable guide member projects outward into the medium transport path from the medium transport surface of the first fixed guide member. 
     
     
       10. The medium transporting apparatus according to  claim 1 , wherein an upstream edge of the first fixed guide member projects toward the first transport member. 
     
     
       11. The medium transporting apparatus according to  claim 1 , wherein the movable guide member is a first movable guide member, the medium transporting apparatus further comprises a second movable guide member that also comes into contact with and guides the medium transported by the first transport member along the medium transport path. 
     
     
       12. The medium transporting apparatus according to  claim 1 , wherein the first position is a position where a front end of the medium transported by the first transport member abuts the movable guide member. 
     
     
       13. A medium transporting apparatus comprising:
 a first transport member that transports a medium; 
 a movable guide member that comes into contact with and guides the medium transported by the first transport member along a curved medium transport path, the movable guide member being movable from a first position to a second position downstream of the first position in the medium transport direction, the movable guide member being plate-like and having a curved surface corresponding to the medium transport path; 
 a first fixed guide member that guides the medium, wherein the movable guide member moves along a medium transport surface of the first fixed guide member, at least a part of the movable guide member projects outward into the medium transport path from the medium transport surface of the first fixed guide member; and 
 a second fixed guide member that opposes the movable guide member across the medium transport path, 
 wherein a distance between the movable guide member and the second fixed guide member in a direction perpendicular to the medium transport direction gradually decreases along the medium transport direction. 
 
     
     
       14. The medium transporting apparatus according to  claim 13 , wherein the first position is a position where a front end of the medium transported by the first transport member abuts the movable guide member. 
     
     
       15. The medium transporting apparatus according to  claim 13 , further comprising a moving member that urges the movable guide member toward the first position. 
     
     
       16. The medium transporting apparatus according to  claim 15 , wherein the moving member is selected from the group of consisting of a spring, a weight, a solenoid and a motor. 
     
     
       17. The medium transporting apparatus according to  claim 13 , further comprising:
 a driving member that moves the movable guide member; 
 a medium detection sensor that detects the position of the medium on the medium transport path; and 
 a controller that controls the driving member based on an output from the medium detection sensor. 
 
     
     
       18. The medium transporting apparatus according to  claim 13 , wherein the driving member is a motor. 
     
     
       19. The medium transporting apparatus according to  claim 13 , wherein the length of the movable guide member in the medium transport direction is less than the length of the shortest medium that can be transported by the medium transporting apparatus. 
     
     
       20. The medium transporting apparatus according to  claim 13 , wherein the movable guide member includes a plurality of ribs that come into contact with the medium and extend in the medium transport direction. 
     
     
       21. The medium transporting apparatus according to  claim 13 , wherein at least part of the movable guide member is adapted to back away from the medium transport path. 
     
     
       22. The medium transporting apparatus according to  claim 13 , wherein at least part of the movable guide member projects outward into the medium transport path from the medium transport surface of the first fixed guide member. 
     
     
       23. The medium transporting apparatus according to  claim 13 , wherein an upstream edge of the first fixed guide member projects toward the first transport member. 
     
     
       24. The medium transporting apparatus according to  claim 13 , wherein the movable guide member is a first movable guide member, the medium transporting apparatus further comprises a second movable guide member that also comes into contact with and guides the medium transported by the first transport member along the medium transport path. 
     
     
       25. An image forming apparatus comprising:
 the medium transporting apparatus according to  claim 13 ; 
 an image-forming section that forms a toner image; 
 a transfer unit that transfers the toner image to the medium transported by the medium transporting apparatus; and 
 a fixing unit that fuses the toner image transferred to the medium into a permanent image. 
 
     
     
       26. An image forming apparatus comprising:
 the medium transporting apparatus according to  claim 1 ; 
 an image-forming section that forms a toner image; 
 a transfer unit that transfers the toner image to the medium transported by the medium transporting apparatus; and 
 a fixing unit that fuses the toner image transferred to the medium into a permanent image.